The study of the expressions of apoptosis and its related protein by knockdown of human immunodeficiency virus-1 vpr gene / 中华传染病杂志

Objective To observe the expression of apoptosis related protein c-inhibitor of apoptosis protein (IAP)2 by RNA interference of human immunodeficiency virus-1 (HIV-1)vpr gene and analyze the apoptosis of Jurkat cells.Methods Vector (NC),HIV-1vpr (vpr),vpr+ pRNAT-U6.1/Neo-vpr-56 (Si56) and vpr+ pRNAT-U6.1/Neo-vpr-160 (Si160) were transfected to Jurkat cells and cultured for 48 hours.The total RNA and protein were extracted.Expression of vpr gene was detected by reverse transcription (RT)-polymerase chain reaction (PCR) to confirm the success of transfection.Expression of c IAP2 was detected by RT-PCR and Western Blot.The apoptosis of Jurkat cells was observed by flow cytometry.Results Expression of vpr gene was detected in vpr,Si56 and Si160 groups.The mRNA expression levels in Si56 and Si160 groups were significantly lower than that in vpr group,which declined 87.2％ and 82.2％,respectively (P＜0.05).The levels of c IAP2 mRNA expression in vpr,Si56 and Si160 groups were increased by 3.75,2.49 and 2.65 folds,respectively,compared to that in NC group.However,the c-IAP2 mRNA expressions in Si56 and Si160 groups were lower than that in vpr group,which declined 33.7％ and 29.5％,respectively (P ＜ 0.05).The c-IAP2 protein expression was consistent with mRNA by immunoblotting,and those in Si56 and Si160 groups were declined 42.2％ and 46.8％,respectively,compared to that in vpr group (P＜0.05).The apoptosis of J urkat cells was detected in all groups.Compared to NC group,the apoptotic rate in vpr group was increased by 1.76 folds.However,the differences of apoptosis rate among NC,Si56 and Si160 groups were not statistically significant (all P＞0.05).Compared to vpr group,the apoptotic rates in Si56 and Si160 were significantly decreased by 19.26％ and 18.05％,respectively (P＜0.05).Conclusions The expression of c-IAP2 could be downregulated by knockdown of HIV-1 vpr gene in transcription and protein levels,and the apoptosis of Jurkat cells is inhibited.

Effect of methylation inhibitor on demethylation pattern of the PD-1 gene in promoter region and PD-1 expression in human T lymphocyte cell line / 中南大学学报(医学版)

OBJECTIVE@#To observe the demethylation effect of demethylation inhibitor 5-azacytidine (5-Zac) on programmed death receptor 1 (PD-1) in Molt-4 cells (T lymphocyte cell line) and to investigate the relationship between DNA demethylation and expression of PD-1.@*METHODS@#Molt-4 cells were cultured in the medium containing different concentrations of 5-Zac(0, 5, 10 μmol/L) for 72 h. According to the concentrations of 5-Zac, the Molt-4 cells were divided into a 0 μmol/L 5-Zac group, a 5 μmol/L 5-Zac group, and a 10 μmol/L 5-Zac group. The expression of PD-1 in Molt-4 cells was detected by flow cytometry and the apoptosis rate was calculated. The mRNA transcription level of PD-1 was detected by real-time polymerase chain reaction; Molt-4 cell DNA in all groups were treated by sodium bisulfite. The PD-1 promoter fragment was amplified by PCR, the amplification fragments were transformed into E. coli., the positive clones were selected for equencing, and the methylation status of the fragments of PD-1 promoter was examined. RESULTS Seventy-two hours after the 5-Zac treatment, the expression rate of PD-1 in the Molt-4 cells in the 0 μmol/L 5-Zac group, the 5 μmol/L 5-Zac group, and the 10 μmol/L 5-Zac group was (1.13 ± 0.01)%, (18.96 ± 1.87)%, and (63.09 ± 6.25)% respectively, in a low concentration-dependent way. The PD-1 mRNA expression level was increased significantly with the 5-Zac treatment. Cells apoptosis showed that:compared with the 0 μmol/L 5-Zac group, the apoptosid rate in the 5 μmol/L 5-Zac group and 10 μmol/L 5-Zac group was signficantly increased, which was (1.9 ± 0.06)%, (8.89 ± 1.36)%, and (24.50 ± 3.68)% in the 0 μmol/L 5-Zac group, the 5 μmol/L 5-Zac group, and the 10 μmol/L 5-Zac mol/L group respectively. The bisulfite genomic sequencing showed that the demethylation probability of CpG points on -601 bp and -553 bp was significantly increased in the 5-Zac treated cells compared with those untreated.@*CONCLUSION@#5-Zac can result in the increase of PD-1 expression in the human lymphoid cell series Molt-4 in vitro, and the apoptosis rate increases, which is related to PD-1 gene promoter demethylation.

5-azacytidine induces PD-1 gene promoter demethylation and PD-1 protein expression in human lymphoid cell series Molt-4 cells / 中华微生物学和免疫学杂志

Objective To investigate the demethylation and changes in gene expression of programmed death receptor-1 ( PD-1) caused by methylation inhibitor 5- azacytidine (5-Zac) in lymphocyte series Molt-4 cells and its mechanism. Methods Molt-4 cells were cultured in different concentrations of 5-Zac(0, 5, 10 Umol/L)for 72 h, ratio of cell expressing PD-1 and apoptosis rate were detected by FCM, transcription of PD-1 gene mRNA was detected by RT-PCR. Molt-4 cell DNA of all groups were disposed by sodium bisulfite, PD-1 gene promoter fragment binded with transcription factor Brn-2 was amplified by PCR,these amplification fragments were transformed into E. coli. Positive clones were selected by sequencing,methylation status of the fragments binded with transcription factor Brn-2 was examined. Results S-Zac could increase the PD-1 expression of Molt-4 cells. PD-1 expression rate in 0 μmol/L 5-Zac( 1. 13%±0.01% ) treated cells was found more lower than that in both 5 μmol/L and 10 μmol/L 5-Zac treated cells (18. 96% ±1. 87% , 63. 09% ± 6. 25% , P < 0. 05 ) , and they showed concentration-dependent (P <0.01). Cells apoptosis rate and PD-1 mRNA expression were also observed increased significantly with 5-Zac treating. Demethylation probability of CG points showed significant difference between transcription factor Brn-2 binding site and other four locations (P < 0.05 ). Conclusion 5 -Zac inhibits cell grouth in human lymphoid cell series Molt-4 by inducing PD-1 gene expression and promoter demethylation. PD-1 gene promoter binding transcription factor Brn-2 fragment CG point demethylation may be one of the important mechanisms in 5-Zac treated Molt-4 cells.

Inhibition of HBV-DNA replication and expression by siRNA based on magnetic nanoparticles transfering in HepG2 2.2.15 cells / 中南大学学报(医学版)

Objective To investigate the inhibitory effect of downregulation of hepatitis B virus (HBV) core gene (HBcAg) expression by RNA interference and magnetic nanoparticles on both HBV DNA replication and expression in vitro. Methods HepG2 2.2.15 cells were transfected with U6 promoter plasmids coding for small interfering RNA (siRNA) targeting HBV core gene using magnetic nanoparticles. RT-PCR and Western blot were used to assess the mRNA and protein expression HBV core antigen. Real-time PCR was used to evaluate the suppression efficiency of HBV-DNA replication and expression; and radioimmunoassay was used for HBV surface antigen (HBsAg), core antigen (HBcAg), and e antigen (HBeAg) detection. Results We successfully constructed nanoparticles with siRNA plasmid targeting HBV core antigen; HBcAg mRNA and HBV core antigen protein levels were significantly reduced in the transfected cells. HBV-DNA downregulation was estimated at 4-5 logs and the HBsAg and HBeAg levels were also reduced compared with the controls. Conclusion Downregulation of HBV core gene using RNAi technology and magnetic nanoparticles can potentially be used as a therapeutic strategy for Hepatitis B.